The present invention relates to tocoperol derivatives and, more particularly, to tocopherol derivatives in which a tocopherol moiety is covalently coupled to a branched hydrophilic moiety.
Surfactants are molecules that are composed of groups of opposing solubility properties. The presence of two structurally dissimilar groups within a single molecule is a defining characteristic of surfactants. Surfactants typically include hydrophobic and hydrophilic groups. In contrast to cationic and anionic surfactants, nonionc surfactants are electronically neutral molecules that do not have a discrete charge when dissolved in aqueous media. The hydrophilicity of nonionic surfactants is provided by hydrogen bonding of the surfactant""s hydrophilic group with water molecules. The hydrophilic groups of the surfactant often include oxygen atoms. Common nonionic surfactants include polyoxyethylene surfactants.
In addition to the hydrophilic portion, the hydrophobic portion of a surfactant can be chosen to achieve the desired surfactant properties. While hydrocarbon chains are a common hydrophobic group, a surfactant""s hydrophobic group can include a variety of organic groups that are relatively hydrophobic.
Tocopherol succinate polyethylene glycol (TPGS) is an example of a nonionic surfactant that includes a tocopherol (vitamin E) hydrophobic group and a poly(oxyethylene) hydrophilic group. While TPGS has been utilized in a variety of surfactant applications, there exists a need for surfactants having improved properties, including surfactants that include tocopherol-based hydrophobic groups and poly(oxyethylene) hydrophilic groups. The present invention seeks to fulfill this need and provides further related advantages.
In one aspect of the invention, a tocopherol derivative is provided. In one embodiment, the tocopherol derivative includes a tocopherol moiety covalently coupled to branched hydrophilic moiety. In another embodiment, the tocopherol derivative includes a first tocopherol moiety covalently coupled to a second tocopherol moiety through a hydrophilic moiety. In other embodiments, the derivative includes three or more tocopherol moieties.
In other aspects of the invention, methods for preparing and using the tocopherol derivatives are provided.